9/16 He cleaned, dried, and weighed this vessel; then he put into it rain-water which he had distilled eight times; he heated the vessel, removing the stopper from time to time to allow the expanding air to escape, then put in the stopper, allowed the vessel to cool, and weighed very carefully. The difference between the second and the first weighing was the weight of water in the vessel. He then fastened the stopper securely with cement, and kept the apparatus at a temperature about 30 deg. below that of boiling water, for a hundred and one days. |